It is known in the field of engine technology to avoid emission of pollutants by partially rerouting exhaust gas to the fresh air side of the engine. Thus, it is necessary to cool the exhaust gas depending on the operational state of the engine. Particularly, it is undesirable at the same time to cool the exhaust gas at low engine temperatures and/or low engine load. For that purpose a bypass is provided bypassing the cooler, wherein a suitable valve setting controls how much exhaust gas flows through the bypass and the cooler, respectively.
A cooler of this sort is known from EP 1 277 945 A1. The cooler comprises a housing having ports to supply and discharge a coolant. Furthermore, a bypass pipe is provided bypassing the cooler in such way that the recirculated exhaust gas at least partially flows through the bypass pipe and is not cooled.
It is an object of the invention to provide an exhaust gas cooler for an exhaust gas recirculation system having an additional duty point.